Method of preparing ITO ceramic target with controllable grain size

Abstract

A method of preparing an ITO ceramic target includes that: In2O3 powder with mass fraction of 90˜97 and SnO2 powder with mass fraction of 10˜3 are ball-milled and mixed with deionized water, diluent, binder and polymer material by a sand mill to obtain an ITO ceramic slurry with a solid content between 70˜80% and a viscosity between 120˜300 mpa·s, with an average particle size D50 of the mixed powder controlled at 100˜300 nm; the ITO ceramic slurry is shaped by a pressure grouting to obtain an ITO ceramic green body with a relative density of 58˜62%; the ITO ceramic green body is put into a degreasing and sintering integrated furnace, and under a degreasing temperature of 700˜800° C., the ITO ceramic target is degreased in an atmospheric oxygen atmosphere for the time set to 12˜36 hours; the temperature increases from the degreasing temperature to the first sintering temperature of 1,600˜1,650° C.

What is claimed is: 
     
       1. A method of preparing an ITO ceramic target with a controllable grain size, comprising:
 ball-milling and mixing In 2 O 3  powder with mass fraction of 90˜97 and SnO 2  powder with mass fraction of 10˜3 with deionized water, diluent, binder and polymer material by a sand mill to obtain an ITO ceramic slurry with a solid content between 70˜80% and a viscosity between 120˜300 mPa·s, with an average particle size D50 of the mixed powder in the ITO ceramic slurry is controlled at 200˜300 nm; 
 shaping the ITO ceramic slurry by a pressure grouting to obtain an ITO ceramic green body with a relative density of 58˜62%; 
 the ITO ceramic green body undergoing an integrated degreasing and sintering treatment to obtain the ITO ceramic target; wherein the integrated degreasing and sintering treatment includes: 
 putting the ITO green body into a degreasing and sintering integrated furnace; 
 heating the degreasing and sintering integrated furnace to a degreasing temperature of 700˜800° C., degreasing the ITO ceramic green body in an atmospheric oxygen atmosphere for a degreasing time set to 12 to 36 hours; 
 increasing the degreasing and sintering integrated furnace from the degreasing temperature to a first sintering temperature of 1,600˜1,650° C.; and 
 after increasing to the first sintering temperature, keeping the temperature at the first sintering temperature for 0˜60 min, then start to reduce the degreasing and sintering integrated furnace from the first sintering temperature to a second sintering temperature of 1,500˜1,540° C., and sintering the ITO target at the second sintering temperature in the atmospheric oxygen atmosphere, with temperature kept for 12 to 36 hours, to finally obtain the ITO ceramic target. 
 
     
     
       2. The method according to  claim 1 , wherein the mass fractions of In 2 O 3  powder and SnO 2  powder are 90 and 10. 
     
     
       3. The method according to  claim 1 , wherein the mass fractions of In 2 O 3  powder and SnO 2  powder are 95 and 5. 
     
     
       4. The method according to  claim 1 , wherein the mass fractions of In 2 O 3  powder and SnO 2  powder are 93 and 7. 
     
     
       5. The method according to  claim 1 , wherein a primary particle size distribution range of the In 2 O 3  powder is 80˜200 nm, and a primary particle size distribution range of the SnO 2  powder is 80˜200 nm. 
     
     
       6. The method according to  claim 1 , wherein the diluent includes polyacrylic or polycarboxylic acid diluent, the binder includes gum arabic, polyvinyl alcohol or acrylic resin, and the polymer material includes polyacrylamide. 
     
     
       7. The method according to  claim 1 , wherein said ball-milling and mixing is performed under vacuum depressurized conditions, the negative pressure not greater than 9 Pa. 
     
     
       8. The method according to  claim 1 , wherein a heating rate from a room temperature to the degreasing temperature is set to 1˜3° C./min. 
     
     
       9. The method according to  claim 1 , wherein a heating rate from the degreasing temperature to the first sintering temperature is set to 2˜5° C./min. 
     
     
       10. The method according to  claim 1 , wherein a cooling rate from the first sintering temperature to the second sintering temperature is set to 8˜16° C./min.